GH-337: Added the JCommander instance to ParameterException so you can call usage() on it.

Fixes https://github.com/cbeust/jcommander/issues/337

2 files changed, 28 insertions, 31 deletions

diff --git a/src/main/java/com/beust/jcommander/JCommander.java b/src/main/java/com/beust/jcommander/JCommander.java
index 8fd455d..eff463a 100644
--- a/src/main/java/com/beust/jcommander/JCommander.java
+++ b/src/main/java/com/beust/jcommander/JCommander.java
@@ -18,42 +18,20 @@
 
 package com.beust.jcommander;
 
+import com.beust.jcommander.FuzzyMap.IKey;
+import com.beust.jcommander.converters.*;
+import com.beust.jcommander.internal.*;
+
 import java.io.BufferedReader;
 import java.io.IOException;
-import java.lang.reflect.Constructor;
-import java.lang.reflect.InvocationTargetException;
-import java.lang.reflect.Method;
-import java.lang.reflect.ParameterizedType;
-import java.lang.reflect.Type;
+import java.lang.reflect.*;
 import java.nio.charset.Charset;
 import java.nio.file.Files;
 import java.nio.file.Paths;
-import java.util.ArrayList;
-import java.util.Arrays;
-import java.util.Collections;
-import java.util.Comparator;
-import java.util.EnumSet;
-import java.util.Iterator;
-import java.util.List;
-import java.util.Locale;
-import java.util.Map;
+import java.util.*;
 import java.util.ResourceBundle;
 import java.util.concurrent.CopyOnWriteArrayList;
 
-import com.beust.jcommander.FuzzyMap.IKey;
-import com.beust.jcommander.converters.DefaultListConverter;
-import com.beust.jcommander.converters.EnumConverter;
-import com.beust.jcommander.converters.IParameterSplitter;
-import com.beust.jcommander.converters.NoConverter;
-import com.beust.jcommander.converters.StringConverter;
-import com.beust.jcommander.internal.Console;
-import com.beust.jcommander.internal.DefaultConsole;
-import com.beust.jcommander.internal.DefaultConverterFactory;
-import com.beust.jcommander.internal.JDK6Console;
-import com.beust.jcommander.internal.Lists;
-import com.beust.jcommander.internal.Maps;
-import com.beust.jcommander.internal.Nullable;
-
 /**
  * The main class for JCommander. It's responsible for parsing the object that contains
  * all the annotated fields, parse the command line and assign the fields with the correct
@@ -306,7 +284,12 @@ public class JCommander {
      * Parse and validate the command line parameters.
      */
     public void parse(String... args) {
-        parse(true /* validate */, args);
+        try {
+            parse(true /* validate */, args);
+        } catch(ParameterException ex) {
+            ex.setJCommander(this);
+            throw ex;
+        }
     }
 
     /**
diff --git a/src/main/java/com/beust/jcommander/ParameterException.java b/src/main/java/com/beust/jcommander/ParameterException.java
index 2bba7d1..41570ff 100644
--- a/src/main/java/com/beust/jcommander/ParameterException.java
+++ b/src/main/java/com/beust/jcommander/ParameterException.java
@@ -26,7 +26,6 @@ package com.beust.jcommander;
  */
 @SuppressWarnings("serial")
 public class ParameterException extends RuntimeException {
-
   public ParameterException(Throwable t) {
     super(t);
   }
@@ -37,6 +36,21 @@ public class ParameterException extends RuntimeException {
   
   public ParameterException(String string, Throwable t) {
       super(string, t);
-  }   
+  }
+
+  private JCommander jc;
+
+  public void setJCommander(JCommander jc) {
+    this.jc = jc;
+  }
+
+  public JCommander getJCommander() {
+    return jc;
+  }
 
+  public void usage() {
+    if (jc != null) {
+      jc.usage();
+    }
+  }
 }